An animatronic Brachiosaurus at the temporary Dinosaur! exhibit at the Minnesota Zoo.

It's name means “arm lizard” because it's forelimbs are longer than it's hind legs

Speculation suggests that Brachiosaurus could have weighed up to 88 tons and measured 85 feet long plus 50 feet of tail. These dinosaurs must have had large and powerful hearts to pump blood all the way up their long necks and back down to the tip of their tails.

What They Ate: Brachiosaurus was an herbivore (plant eater) and most likely dined on foliage like conifers, tree ferns and ginkgoes. Considering its long neck, these trees were probably in the 16 foot height range.

Where Fossils Have Been Found In North America: Colorado

What They Did: Paleontologists believe that Brachiosaurus was a gregarious animal and lived in herds or families. While the size of a healthy adult made it unlikely prey, youngsters would have been vulnerable and that is perhaps a reason for living in groups.

How They Are Doing: Extinct. Lived in the Jurassic Period, 156-145 million years ago.